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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>规定总款度为250像素的元素</title>
</head>

<body>

    <style>
        div {
            width: 320px;
            padding: 10px;
            border: 5px solid gray;
            margin: 0;
        }
    </style>

    <h1>计算总宽度：</h1>

    <img src="../WechatIMG4.jpeg" width="350" height="263" alt="Klematis">

    <div>上面的图片宽 350 像素。此因素的总宽也是 350 像素。</div>
</body>

</html>